The purpose of this study is to develop key components that can be used in a
magnetic resonance microsystem. Conventional magnetic resonance systems comprise
several components including a superconducting magnet, RF amplifier, spectrometer, and
probe head. This study proposes a magnetic resonance microsystem that uses NdFeB
permanent magnet material to replace the superconducting magnet, and an on-chip RF
amplifier and microfabricated coils as the probe head.
This study focuses on the design and fabrication of the key components of RF
microcoils and gradient microcoils. A multilayer high-aspect-ratio metal fabrication
process is developed to fabricate a nanoliter-volume radio frequency (RF) saddle coil
with an embedded flow-through fluidic channel for magnetic resonance applications. The
measured resistance of the RF microcoil and the 1H spectrum line width are 0.7 Ω and
350 Hz, respectively. The results indicate that this novel fabrication process for
microcoils is feasible for magnetic resonance applications. These key components can be
used to realize magnetic resonance microsystems in the future.

本論文之主要研究目的為開發可應用於微型化之核磁共振系統之關鍵零組件。傳統核磁共振系統包含了超導磁鐵、射頻放大訊號放大器、商用光譜儀、射頻探頭等元件。本研究所提出之微型化系統使用等級N42之銣鐵硼(NdFeB)材料組裝成永久磁鐵代替超導磁鐵，以及晶片化射頻放大器，和使用微製程所製造之射頻線圈及梯度線圈探頭。 本論文主要著重於射頻線圈和梯度線圈等關鍵元件之微型化設計與製造。微型化之射頻和梯度線圈使用多層高深寬比之金屬微製程技術所製造，在此微線圈中並製作一微流體通道使液體樣品流過。此微型射頻線圈之電阻值為0.7歐姆而在核磁共振實驗中量測得到的氫原子譜線寬度為350 Hz。本論文之研究結果顯示出利用上述之關鍵元件以實現微型化核磁共振系統之可行性。

1. Olson D L, Peck T L, Webb A G, Magin R L, Sweedler J V (1995)
High-Resolution Microcoil H-NMR for Mass-Limited, Nanoliter-Volume Samples.
Science. 270(5244):1967-1970.
2. Lacey M E, Subramanian R, Olson D L, Webb A G, Sweedler J V (1999)
High-resolution NMR spectroscopy of sample volumes from 1 nL to 10 □L. Chem.
Rev. 99 (10):3133-3152
3. Peck T L, Magin R L, Lauterbur P C (1995) Design and analysis of microcoils for
NMR microscopy. Journal of magnetic resonance. Series B 108: 114-124.
4. Badilita V, Kratt K, Burger T, Korvink J G, Wallrabe U 3D high aspect ratio,
MEMS integrated micro-solenoids and Helmholtz micro-coils. In: The 15th
International Conference on Solid-State Sensors, Actuators and Microsystems
(Transducers’09) Denver (U.S.A.), June 21–25, 2009, pp. 1106-1109
5. Demas V, Herberg J L, Malba V, Bernhardt A, Evans L, Harvey C, Chinn S C,
Maxwell R S, Reimer J (2007) Portable, low-cost NMR with laser-lathe
lithography produced microcoils. J. Magn. Reson. 189:121-129
6. Goto S, Matsunaga T, Matsuoka Y, Kuroda K, Esashi M, Haga Y, Development of
high-resolution intraluminal and intravascular MRI probe using microfabrication
on cylindrical substrates, In: IEEE MEMS 2007, Kobe (Japan), Janurary 21-25,
2007, pp. 329-332
7. Jackman R J, Brittain S T, Whitesides G M (1998) Fabrication of
three-dimensional microstructures by electrochemically welding structures formed
by microcontact printing on planar and curved substrates. Journal of
Microelectromechanical Systems 7:261-266
8. Jiang Y G, Ono T, Esashi M (2006) High aspect ratio spiral microcoils fabricated
by a silicon lost molding technique. J. Micromech. Microeng.16:1057-1061
9. Malba V, Maxwell R, Evans L B, Bernhardt A F, Cosman M, Yan K (2003)
Laser-lathe lithography - a Novel method for manufacturing nuclear magnetic
resonance microcoils. Biomedical Microdevices 5(1):21-27
10. Woytasik M, Ginefri J C, Raynaud J S, Poirier-Quinot M, Dufour-Gergam E,
Grandchamp J, Girard O, Robert P, Gilles J P, Martincic E, Darrasse L (2007)
Characterization of flexible RF microcoils dedicated to local MRI. Microsyst.
Technol 13:1575-1580
11. Ehrmann K, Saillen N, Vincent F, Stettler M, Jordan M, Wurm F M, Besse P-A,
Popovic R (2007) Microfabricated solenoids and Helmholtz coils for NMR
spectroscopy of mammalian cells. Lap Chip 7:373-380
12. Massin C, Vincent F, Homsy A, Ehrmann K, Boero G, Besse P-A, Daridon A,
78
Verpoorte E, de Rooij N F, Popovic R S (2003) Planar microcoil-based
microfluidic NMR probes. J. Magn. Reson. 164:242-255
13. Lam M H C, Homenuke M A, Michael C A, Hansen C L (2009) Sub-nanoliter
nuclear magnetic resonance coils fabricated with multilayer soft lithography.
Journal of Micromechanics and Microengineering
doi:10.1088/0960-1317/19/9/095001
14. Li Y, Ahmad M M, Hand J W, Syms R R A, Gilderdale D, Collins D J, Young I R
(2007) Microcoils on structured silicon substrates for magnetic resonance
detection. IEEE Sensors Journal 7(9):1362-1369
15. Jin J M (1999) Electromagnetic Analysis and Design in Magnetic Resonance
Imaging. CRC Press.
16. Bloch F (1946) Nuclear induction. Physical Review. 70:460-474.
17. Hoult D I, Richards R E (1976) The Signal to Noise Ratio of the Nuclear
Magnetic Resonance Experiment. Journal of magnetic resonance. 24:71-85.
18. Fan L S, Hsu S S H, Jin J E, Hsieh C Y, Lin W C, Hao H C, Cheng H L, Hsueh K
C, Lee C Z: Solid-State Circuits Conference, 2007. ISSCC 2007. Digest of
Technical Papers. IEEE International, 2007, p. 166.
19. Fateh B (2006) “Modeling, Simulation and Optimization of a Microcoil for
MRI-Cell Imaging”, Master thesis, IMTEK, Freiburg university-Germany
20. Minard K.R., Wind R.A. (2001) Solenoidal Microcoil Design. Part Ι :
Optimizing RF Homogeneity and Coil Dimensions. Concepts in Magnetic
Resonance. 13(2): 128-142.
21. Morris D, Gorkov P G, Harris A B, Tsao J, Moser K, Georgiadis J, Webb A
Lauterbur,P C (1999) Microsamples, micro-coils, micro-magnets: where will all
this smallness end? L16, In Book of Abstracts for 5th International Conf. on
Magnetic Resonance Spectroscopy (Heidelberg).
22. Glover P, Mansfield S.P. (2002) Limits to magnetic resonance microscopy. Rep.
Prog. Phys. 65:1489-1511.
23. Tuner R, (1993) Gradient Coil Design: A Review of Methods. Magnetic
Resonance Imaging, Vol. 11, pp. 903-920.
24. Valtier M, Humbert F, Canet D, (1999) Maps of self-diffusion coefficients by
radiofrequency field gradient NMR microscopy J. Magn. Reson. 141:7–17
25. Ginsberg D M, Melchner M J (1970) Optimum geometry of saddle shaped coils
for generating a uniform magnetic field. Rev. Sci. Instrum. 41:122-123
26. Lee W., Gao Y., Hirano T., Chan T., S., Fan L.S., (1997) High aspect ratio etching
in polymer for microactuator application, in Proc. Micromachining and
Microfabrication Process Technol., SPIE, pp. 110–117.
27. Yoon J.B., Han C.H., Yoon E., Kim C.K.,(1999) Monolithic integration of 3-D
79
electroplated microstructures with unlimited number of levels using planarization
with a sacrificial metallic mold (PSMM), in Proc IEEE MEMS, Orlando (USA),
pp.624-629
28. Cohen A L, Frodis U, Tseng F G, Zhang G, Mansfeld F, Will P M (1999) EFAB:
low-cost automated electrochemical batch fabrication of arbitrary 3D
microstructures. Proc. SPIE Micromachining and Microfabrication Process
Technology. 3874:236-247.
29. Kim Y, Llamas-Garro I, Baek C W, Kim J M, Kim Y K (2009) New release
technique of a thick sacrificial layer and residue effects on novel half-coaxial
transmission line filters. J. Micromech. Microeng. 19:1-6
30. Bu M, Melvin T, Ensell G J, Wilkinson J S, Evans A G R (2004) A new masking
technology for deep glass etching and its microfluidic application. Sensors and
Actuators A: Physical 115:476-482
31. Iliescu C, Jing J, Tay F E H, Miao J, Sun T (2005) Characterization of masking
layers for deep wet etching of glass in an improved HF/HCl solution. Surface and
Coatings Technology 198:314-318
32. Song J S, Lee S, Jung S H, Cha G C, Mun M S (2009) Improved biocompatibility
of parylene-C files prepared by chemical vapor deposition and the subsequent
plasma treatment. Journal of Applied Polymer Science 112:3677-3685
33. Moresi G, Magin R L(2003) Miniature Permanent Magnet for Table-top NMR
Concepts in Magnetic Resonance Part B, 19B(1):35-43.
34. 林偉成, ”A 4 Tesla Compact Magnet for Nano-MRI”, 碩士論文, 國立清華大學
微機電系統工程研究所, 台灣, 2006.
35. Seeber D A, Hoftiezer J H, Daniel W B, Rutgers M A, Pennington C H (2000)
Triaxial magnetic field gradient system for microcoil magnetic resonance imaging.
Rev. Sci. Instrum. 71:4263-4272
36. Carlson, J W,Derby, K A, Hawryszko, K C, Weideman, M D (1992) Evaluation of
shielded gradient coils. Magn. Reson. Med. 26:191-206.
37. Turner, R (1988) Minimum inductance coils. J. Phys. E: Sci. Instrum. 21:948-952.
38. Olson D L, Lacey M E, Sweedler J V (1998) High-resolution microcoil NMR for
analysis of mass-limited, nanoliter samples. Anal. Chem. 70:645-650
39. Purea A., Neuberger T., Webb A.G., (2004) Simultaneous NMR microimagimg of
multiple single-cell samples. Concept Magn. Reson Eng. 22B:7–14.